xref: /titanic_41/usr/src/uts/common/syscall/symlink.c (revision 4202ea4b139fb1fab45cd14d9d03a81b86902341)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * Portions of this source code were derived from Berkeley 4.3 BSD
31  * under license from the Regents of the University of California.
32  */
33 
34 #pragma ident	"%Z%%M%	%I%	%E% SMI"
35 
36 #include <sys/param.h>
37 #include <sys/isa_defs.h>
38 #include <sys/types.h>
39 #include <sys/sysmacros.h>
40 #include <sys/systm.h>
41 #include <sys/errno.h>
42 #include <sys/pathname.h>
43 #include <sys/vfs.h>
44 #include <sys/vnode.h>
45 #include <sys/proc.h>
46 #include <sys/uio.h>
47 #include <sys/debug.h>
48 #include <c2/audit.h>
49 #include <fs/fs_subr.h>
50 
51 /*
52  * Create a symbolic link.  Similar to link or rename except target
53  * name is passed as string argument, not converted to vnode reference.
54  */
55 int
56 symlink(char *target, char *linkname)
57 {
58 	vnode_t *dvp;
59 	struct vattr vattr;
60 	struct pathname lpn;
61 	char *tbuf;
62 	size_t tlen;
63 	int error;
64 	int estale_retry = 0;
65 
66 top:
67 	if (error = pn_get(linkname, UIO_USERSPACE, &lpn))
68 		return (set_errno(error));
69 	if (error = lookuppn(&lpn, NULL, NO_FOLLOW, &dvp, NULLVPP)) {
70 		pn_free(&lpn);
71 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
72 			goto top;
73 		return (set_errno(error));
74 	}
75 	if (vn_is_readonly(dvp))
76 		error = EROFS;
77 	else if (pn_fixslash(&lpn))
78 		error = ENOTDIR;
79 	else {
80 		tbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
81 		if ((error = copyinstr(target, tbuf, MAXPATHLEN, &tlen)) == 0) {
82 			vattr.va_type = VLNK;
83 			vattr.va_mode = 0777;
84 			vattr.va_mask = AT_TYPE|AT_MODE;
85 			error = VOP_SYMLINK(dvp, lpn.pn_path, &vattr,
86 			    tbuf, CRED(), NULL, 0);
87 			if (audit_active)
88 				audit_symlink_create(dvp, lpn.pn_path,
89 				    tbuf, error);
90 		}
91 		kmem_free(tbuf, MAXPATHLEN);
92 	}
93 	pn_free(&lpn);
94 	VN_RELE(dvp);
95 	if (error) {
96 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
97 			goto top;
98 		return (set_errno(error));
99 	}
100 	return (0);
101 }
102